voxelotl-engine/Sources/Voxelotl/Player.swift

356 lines
12 KiB
Swift

import simd
struct Player {
static let height: Float = 1.8
static let radius: Float = 0.22
static let bounds = AABB(
from: .init(-Self.radius, 0, -Self.radius),
to: .init(Self.radius, Self.height, Self.radius))
static let eyeLevel: Float = 1.4
static let epsilon = Float.ulpOfOne * 4000
static let stepHeight: Float = 0.05
static let accelerationCoeff: Float = 86.6
static let airAccelCoeff: Float = 3
static let gravityCoeff: Float = 20
static let frictionCoeff: Float = 0.7375
static let flySpeedCoeff: Float = 36
static let jumpVelocity: Float = 7
static let maxVelocity: Float = 160
static let blockReach: Float = 3.8
private var _position = SIMD3<Float>.zero
private var _velocity = SIMD3<Float>.zero
private var _rotation = SIMD2<Float>.zero
private var _onGround: Bool = false
private var _shouldJump: Optional<Float> = .none
private var _useMouseDir: Bool = false
public var rayhitPos: Optional<SIMD3<Float>> = nil
private var prevLeftTrigger: Float = 0, prevRightTrigger: Float = 0
public var position: SIMD3<Float> { get { self._position } set { self._position = newValue } }
public var velocity: SIMD3<Float> { get { self._velocity } set { self._velocity = newValue } }
public var rotation: SIMD2<Float> { get { self._rotation } set { self._rotation = newValue } }
public var eyePosition: SIMD3<Float> { self._position + .up * Self.eyeLevel }
public var eyeRotation: simd_quatf {
.init(angle: self._rotation.y, axis: .right) *
.init(angle: self._rotation.x, axis: .up)
}
enum JumpInput { case off, press, held }
private mutating func tryMove(_ deltaTime: Float, _ world: World, newPosition: SIMD3<Float>) {
//let oldPosition = self._position
func checkCollision(_ world: World, _ position: SIMD3<Float>) -> Optional<AABB> {
let bounds = Self.bounds + position
let corners: [SIMD3<Float>] = [
.init(bounds.left, bounds.bottom, bounds.far),
.init(bounds.right, bounds.bottom, bounds.far),
.init(bounds.left, bounds.bottom, bounds.near),
.init(bounds.right, bounds.bottom, bounds.near),
.init(bounds.left, bounds.center.y, bounds.far),
.init(bounds.right, bounds.center.y, bounds.far),
.init(bounds.left, bounds.center.y, bounds.near),
.init(bounds.right, bounds.center.y, bounds.near),
.init(bounds.left, bounds.top, bounds.far),
.init(bounds.right, bounds.top, bounds.far),
.init(bounds.left, bounds.top, bounds.near),
.init(bounds.right, bounds.top, bounds.near)
]
for corner in corners {
let blockPos = SIMD3(floor(corner.x), floor(corner.y), floor(corner.z))
if case BlockType.solid = world.getBlock(at: SIMD3<Int>(blockPos)).type {
let blockGeometry = AABB(from: blockPos, to: blockPos + 1)
if bounds.touching(blockGeometry) {
return blockGeometry
}
}
}
return nil
}
func checkCollisionRaycast(_ world: World, _ position: SIMD3<Float>, top: Bool) -> Optional<RaycastHit> {
let dir: SIMD3<Float> = !top ? .down : .up
let hHeight = Self.height * 0.5
var org = self._position + .up * hHeight
let max: Float = hHeight + Self.epsilon * 4
org.x -= Self.radius
org.z -= Self.radius
if let hit1 = raycast(world: world, origin: org, direction: dir, maxDistance: max) { return hit1 }
org.x += Self.radius + Self.radius
if let hit2 = raycast(world: world, origin: org, direction: dir, maxDistance: max) { return hit2 }
org.x -= Self.radius + Self.radius
org.z += Self.radius + Self.radius
if let hit3 = raycast(world: world, origin: org, direction: dir, maxDistance: max) { return hit3 }
org.x += Self.radius + Self.radius
if let hit4 = raycast(world: world, origin: org, direction: dir, maxDistance: max) { return hit4 }
return nil
}
var testPos: SIMD3<Float>
#if false
self._position.y = newPosition.y
if self._velocity.y <= 0, let hit = checkCollisionRaycast(world, self._position, top: false)
{
self._position.y = hit.position.y
self._velocity.y = 0.0
self._onGround = true
} else {
self._onGround = false
}
if self._velocity.y >= 0, let hit = checkCollisionRaycast(world, self._position, top: true)
{
self._position.y = hit.position.y - Self.height
self._velocity.y = 0.0
}
#else
self._position.y = newPosition.y
testPos = self._position
if self._velocity.y > 0 { testPos.y -= Self.epsilon }
if let aabb = checkCollision(world, testPos) {
if self._velocity.y <= 0 {
self._position.y = aabb.top + Self.epsilon
self._onGround = true
} else {
self._position.y = aabb.bottom - Self.height - Self.epsilon
self._onGround = false
}
self._velocity.y = 0
} else if checkCollisionRaycast(world, testPos, top: false) == nil {
self._onGround = false
}
#endif
self._position.x = newPosition.x
testPos = self._position
//testPos.y += self._onGround ? Self.epsilon + Self.stepHeight : -Self.epsilon
if let aabb = checkCollision(world, testPos) {
if self._velocity.x < 0 {
self._position.x = aabb.right + Self.radius + Self.epsilon
} else {
self._position.x = aabb.left - Self.radius - Self.epsilon
}
self._velocity.x = 0
}
self._position.z = newPosition.z
testPos = self._position
//testPos.y += self._onGround ? Self.epsilon + Self.stepHeight : -Self.epsilon
if let aabb = checkCollision(world, testPos) {
if self._velocity.z < 0 {
self._position.z = aabb.near + Self.radius + Self.epsilon
} else {
self._position.z = aabb.far - Self.radius - Self.epsilon
}
self._velocity.z = 0
}
}
private mutating func moveGround(_ deltaTime: Float, _ world: World, moveDir accelDir: SIMD2<Float>) {
// Calculate coefficients
let reference: Float = 60.0
let invReference = 1 / reference
let dtReference = deltaTime * reference
let friction = Self.frictionCoeff
let fricPowRef = pow(friction, dtReference)
let fricMin1 = friction - 1
let fricPowRefMin1 = fricPowRef - 1
// Integration steps
func integratePosition(_ acceleration: SIMD2<Float>, _ position: SIMD2<Float>, _ velocity: SIMD2<Float>
) -> SIMD2<Float> {
var stepMul = acceleration * (friction * fricPowRef - friction * (dtReference + 1) + dtReference)
stepMul += fricMin1 * velocity * fricPowRefMin1
let step = (friction * stepMul) / (fricMin1 * fricMin1)
return position + step * invReference
}
func integrateVelocity(_ accleration: SIMD2<Float>, _ velocity: SIMD2<Float>) -> SIMD2<Float> {
velocity * fricPowRef + accleration * (friction * fricPowRefMin1 / fricMin1)
}
// Perform integration
let acceleration = accelDir * Self.accelerationCoeff * invReference
var nextPosition = self._position
nextPosition.xz = integratePosition(acceleration, self._position.xz, self._velocity.xz)
nextPosition.y += self.velocity.y * deltaTime // Hack
self._velocity.xz = integrateVelocity(acceleration, self._velocity.xz)
// Handle collision
tryMove(deltaTime, world, newPosition: nextPosition)
}
private mutating func moveAir(_ deltaTime: Float, _ world: World, moveDir accelDir: SIMD2<Float>) {
var forceSum: SIMD3<Float> = .zero
// Apply movement
let scaled = accelDir * Self.airAccelCoeff
forceSum += SIMD3(scaled.x, 0, scaled.y)
// Apply gravity
forceSum += .down * Self.gravityCoeff
// Classic semi-implicit euler integration
self._velocity += forceSum * deltaTime
let nextPosition = self._position + self._velocity * deltaTime
// Handle collision
tryMove(deltaTime, world, newPosition: nextPosition)
}
mutating func update(deltaTime: Float, world: World, camera: inout Camera) {
var turning: SIMD2<Float> = .zero
var movement: SIMD2<Float> = .zero
var flying: Int = .zero
var jumpInput: JumpInput = .off
var destroy = false, place = false
// Read controller input (if one is plugged in)
if let pad = GameController.current?.state {
let turn = pad.rightStick.radialDeadzone(min: 0.1, max: 1)
if turn != .zero {
turning += turn
self._useMouseDir = false
}
movement = pad.leftStick.cardinalDeadzone(min: 0.1, max: 1)
flying += (pad.down(.rightBumper) ? 1 : 0) - (pad.down(.leftBumper) ? 1 : 0)
if pad.pressed(.east) {
jumpInput = .press
} else if jumpInput != .press && pad.down(.east) {
jumpInput = .held
}
if pad.leftTrigger > 0.4 && prevLeftTrigger < 0.4 {
place = true
}
if pad.rightTrigger > 0.4 && prevRightTrigger < 0.4 {
destroy = true
}
prevLeftTrigger = pad.leftTrigger
prevRightTrigger = pad.rightTrigger
}
// Read keyboard input
if Keyboard.down(.w) { movement.y -= 1 }
if Keyboard.down(.s) { movement.y += 1 }
if Keyboard.down(.a) { movement.x -= 1 }
if Keyboard.down(.d) { movement.x += 1 }
if Keyboard.down(.q) { flying += 1 }
if Keyboard.down(.e) { flying -= 1 }
if Keyboard.pressed(.tab) { Mouse.capture = !Mouse.capture }
if Keyboard.pressed(.space) {
jumpInput = .press
} else if jumpInput != .press && Keyboard.down(.space) {
jumpInput = .held
}
if Keyboard.pressed(.leftBracket, repeat: true) {
self._position *= 2
}
// Read mouse input
if Mouse.pressed(.left) { destroy = true }
if Mouse.pressed(.right) { place = true }
if Mouse.capture {
self._rotation += Mouse.relative / 2048 * Float.pi
self._useMouseDir = false
} else if simd_length_squared(Mouse.relative) > Float.ulpOfOne {
self._useMouseDir = true
}
// Turning input
self._rotation += turning * deltaTime * 3.0
if self._rotation.x < 0.0 {
self._rotation.x += .pi * 2
} else if _rotation.x > .pi * 2 {
self._rotation.x -= .pi * 2
}
self._rotation.y = self._rotation.y.clamp(-.pi * 0.5, .pi * 0.5)
// Jumping
if jumpInput == .press {
self._shouldJump = 0.3
} else if self._shouldJump != .none {
if jumpInput == .held {
self._shouldJump! -= deltaTime
if self._shouldJump! <= 0.0 {
self._shouldJump = .none
}
} else {
self._shouldJump = .none
}
}
let willJump: Bool
if self._onGround && self._shouldJump != .none {
self._shouldJump = .none
willJump = true
} else {
willJump = false
}
// Movement/integration
// Limit unscaled movement vector to one
let movementMagnitude = simd_length(movement)
if movementMagnitude > 1.0 {
movement /= movementMagnitude
}
// Rotate movement vector
let right = SIMD2(cos(self._rotation.x), sin(self._rotation.x))
movement = (right * movement.x + SIMD2(-right.y, right.x) * movement.y)
// Flying and unflying
self._velocity.y += Float(flying).clamp(-1, 1) * Self.flySpeedCoeff * deltaTime
// Apply physics
let iterations = 1
let iterDT = deltaTime / Float(iterations)
for _ in 0..<iterations {
if self._onGround {
self.moveGround(iterDT, world, moveDir: movement)
} else {
self.moveAir(iterDT, world, moveDir: movement)
}
// Limit maximum velocity
let velocityLen = simd_length(self._velocity)
if velocityLen > Self.maxVelocity {
self._velocity = self._velocity / velocityLen * Self.maxVelocity
}
}
// Jumping
if self._onGround && willJump {
self._velocity.y = Self.jumpVelocity
self._onGround = false
}
// Update camera
camera.position = self.eyePosition
camera.rotation = self.eyeRotation
// Block picking
let dir = !Mouse.capture && self._useMouseDir
? camera.screenRay(Mouse.position)
: self.eyeRotation * .forward
if let hit = raycast(world: world, origin: self.eyePosition, direction: dir, maxDistance: Self.blockReach) {
if destroy || place {
if destroy {
world.setBlock(at: hit.map, type: .air)
} else {
world.setBlock(at: hit.map.offset(by: hit.side), type: .solid(.white))
}
if let hit = raycast(world: world, origin: self.eyePosition, direction: dir, maxDistance: Self.blockReach) {
self.rayhitPos = hit.position
} else {
self.rayhitPos = nil
}
} else {
self.rayhitPos = hit.position
}
} else {
self.rayhitPos = nil
}
}
}